Dermatology · Systemic retinoid
Isotretinoin
Dose
0.5 mg/kg/day PO with food, increasing to 1 mg/kg/day; cumulative target 120–150 mg/kg.
Contraindications
- • Pregnancy
- • Concurrent tetracyclines (intracranial hypertension)
Use
Severe nodulocystic or scarring acne unresponsive to antibiotics.
Monitoring
Pregnancy test monthly, lipids and LFTs at baseline and 8 weeks, mood review.
Side effects
- • Dry lips, skin and eyes
- • Hypertriglyceridaemia
- • Myalgia
- • Mood disturbance
Pregnancy safety
Absolutely contraindicated — pregnancy prevention programme mandatory.
Always confirm dose against your local formulary / BNF before prescribing.
